基于多线组宽带模型与积分微分混合算法的喷管远程红外成像计算

针对现有宽带k分布模型不适合高温喷流3~5μm波段发射辐射在大气中远距离传输衰减特性计算的问题,将之前用于全光谱模型的多线组技术应用于宽带模型,并对光谱吸收系数的分组优化状态点进行了针对性调整。无限宽度多层气体辐射特性一维/准一维算例的计算结果表明,多线组技术可大幅提高原始全光谱与宽带模型对强非均匀气体辐射特性的计算精度,同时保持对灰体固壁辐射的良好兼容性。以此为基础,对带冷却装置Ⅴ形尾缘收缩喷管的耦合换热特性和远程红外特性进行了数值研究,结果表明:气体辐射对喷管固壁温度分布的影响不能忽略；多线组宽带模型对跨声速排气系统70km红外成像的预测误差在7%左右。 

Calculation of nozzle remote infrared imaging based on multi-scale multi-group wideband model and integrated differential hybrid algorithm

To solve the problem that existing k distribution model is not suitable for high temperature flow 3-5μm wave band emission radiation transmission attenuation characteristic in atmospheric long distance calculation,multi-scale multi-group technology used in full-spectrum model before was applied in wideband model, and the grouping state points on the spectral absorption coefficient were adjusted.The calculation results of one-dimensional/quasi one-dimensional numerical example of infinite width multilayer gas radiation characteristics show that multi-scale multi-group technology can improve the calculation precision of original full spectrum and wideband model while keeping compatibility with rational of gray wall. On this basis, the coupling heat transfer characteristics and the remote infrared characteristics of V nozzle trailing edge contraction with cooling device were studied. The results show that the gas radiation effect on the solid wall temperature distribution in the nozzle can not be ignored. The prediction error of the remote infrared images for transonic exhaust system at 70km with use of the multi-scale multi-group wideband model is about 7%.